Error occurs when open built app: Could not get code signature for running application

After I run $ yarn build

and open cra-electron.app

Did you ever find a fix for this?

I had the same issue, but I found the solution. I believe it is related to code signing on macOS:

1. Delete existing build folder (if you've already tried to yarn build)
2. In the file "/public/electron.js/", remove the code:-

require("update-electron-app")({
  repo: "kitze/react-electron-example",
  updateInterval: "1 hour"
});

3. Do a yarn build and the app in the dist folder should be working now. Hope it works for you too.

Also try to remove the build option from the package.json